JP2009041413A - Oil control valve control device - Google Patents

Abstract

【Task】
This is to prevent malfunction due to foreign matter clogging of the variable valve timing mechanism.
[Solution]
In an internal combustion engine equipped with a variable valve timing mechanism, when the actuator is feedback controlled so that the actual cam phase matches the target cam phase calculated according to the engine operating condition, the target is determined by the change in the engine operating condition. When the cam phase changes, the actuator is controlled with a predetermined control value different from the feedback control for a predetermined time thereafter.
[Selection] Figure 7

Description

  The present invention relates to an apparatus for controlling an oil control valve of an internal combustion engine.

  As a mechanism for adjusting the opening / closing timing of the intake / exhaust valve of the internal combustion engine (hereinafter referred to as a variable valve timing mechanism), a mechanism using hydraulic pressure is known. In this mechanism, an oil control valve is provided to control the hydraulic pressure. It is done. This oil control valve includes an input port to which hydraulic pressure is supplied from an oil pump, an output port for outputting regulated hydraulic pressure, a drain port, and the like. In the state in which the output hydraulic pressure is regulated, the input port or drain Since the opening width of the port may be extremely small, for example, about several tens of μm, foreign matters such as metal powder and sludge mixed in the oil get caught in the small opening, causing malfunction of hydraulic control. .

  If a malfunction occurs when the oil control valve is feedback controlled so that the intake / exhaust valve opening / closing timing matches the target, the intake / exhaust valve opening / closing timing will deviate from the target. Even if it is attempted to move the spool in a decreasing direction, the actual spool position is fixed due to the catch of the foreign matter, and the foreign matter is caught by this feedback control and cannot flow out.

  Therefore, while the feedback control is continued, the opening / closing timing of the intake / exhaust valve continues to deviate from the target, which may deteriorate the output characteristics and exhaust of the internal combustion engine.

  In order to prevent such malfunction, when it is determined that the valve timing changing operation by the variable valve timing mechanism is abnormal, the spool of the oil control valve is moved greatly to open the opening, and foreign matter is discharged together with oil. A technique is known (for example, Patent Document 1). In Patent Document 1, an abnormality of the oil control valve is detected due to the opening / closing timing of the intake / exhaust valve being different from the target, and the position of the spool of the oil control valve is repeatedly changed within a predetermined fluctuation range. A control technique is disclosed.

Japanese Patent No. 3098676

  However, in the above-described conventional control technology, the control for greatly moving the spool of the oil control valve to open the opening and discharging foreign matter together with oil (hereinafter referred to as foreign matter discharge control) is performed only after the abnormality is detected. Since there is no effect to prevent clogging of foreign matter, the opening and closing timing of the intake / exhaust valve will be different from the target until it is detected after the clogging of foreign matter is detected and discharged. There is a risk that the output characteristics and exhaust of the internal combustion engine will deteriorate.

  Furthermore, the conventional foreign matter discharge control creates a state in which the intake / exhaust valve opening / closing timing is different from the target, so that the output characteristics and exhaust of the internal combustion engine deteriorate while the foreign matter discharge control is performed. There is a risk of doing.

  Therefore, the present invention can prevent foreign matter from being clogged in advance by performing foreign matter discharge control regardless of whether or not the valve timing changing operation is abnormal. Is possible.

  According to the present invention, it is possible to suppress the influence on the output characteristics of the internal combustion engine and the deterioration of the exhaust gas as compared with the prior art even during the foreign matter discharge control.

  The best mode for carrying out the present invention will be described below.

  As the first embodiment, the oil control valve control device performs feedback control of the actuator so that the actual cam phase matches the target cam phase calculated according to the engine operating condition. When the target cam phase changes due to the change, the actuator is controlled with a predetermined control value different from the feedback control only for a predetermined time thereafter.

  By adopting such a configuration, the foreign matter discharge control is performed regardless of whether or not the valve timing changing operation is abnormal, so that a stage before a clear abnormality occurs in the valve timing changing operation due to the foreign matter. The foreign matter can be removed by this, and the output characteristics of the internal combustion engine and the deterioration of the exhaust gas can be prevented.

  Even if an abnormality has already occurred in the valve timing changing operation due to foreign matter, the foreign matter discharge control is performed by interrupting the feedback control regardless of whether the valve timing changing operation is abnormal. And the deterioration of the output characteristics of the internal combustion engine and the exhaust gas can be prevented.

  As a second embodiment, in addition to the features of the first embodiment, the oil control valve control device operates in the advance direction when the change direction of the target cam phase is the advance direction. Such a control value is set as the predetermined control value. Conversely, when the change direction of the target cam phase is the retarded direction, the control value is set so that the rotational phase of the cam shaft also operates in the retarded direction. It is characterized by.

  As a third embodiment, the oil control valve control device has a small change amount when the change amount per unit time of the target cam phase is large in addition to the features of the first embodiment and the second embodiment. In this case, the predetermined time is controlled as a longer time than the above.

  If foreign matter discharge control is performed regardless of whether or not the valve timing changing operation is abnormal, it may cause a divergence between the target cam phase and the actual cam phase. In the second embodiment, the target cam phase The actuator is controlled so that the rotational phase of the camshaft changes in the same direction as the phase change direction. Furthermore, in the third embodiment, only the optimal time according to the amount of change per unit time of the target cam phase. Since the foreign matter discharge control is performed, the deviation between the target cam phase and the actual cam phase is minimized.

  As a fourth embodiment, the oil control valve control device controls the actuator with a predetermined control value different from the feedback control in addition to the features of the first to third embodiments. It is characterized in that it is carried out at a frequency less than the frequency of changes.

  Even if the countermeasures of the second embodiment and the third embodiment are implemented, the foreign matter discharge control is continuously performed when the operation state change occurs such that the target cam phase changes a plurality of times in a short time. Since the deviation between the target cam phase and the actual cam phase may become large, the countermeasures of the fourth embodiment are implemented to reduce the frequency of foreign matter discharge control and continuously Can be avoided, and the deviation between the target cam phase and the actual cam phase is minimized.

  As a fifth embodiment, the oil control valve control device is different from the feedback control in the period from the start to the stop of the internal combustion engine in addition to the features of the first to fourth embodiments. The number of times the actuator is controlled with the control value is limited to a predetermined number or less.

  In an internal combustion engine used in a hybrid vehicle having both an internal combustion engine and an electric motor as power, the target cam phase may also change in a preset pattern due to a characteristic change in operating state at the time of starting and immediately after the starting. Therefore, in the fifth embodiment, the foreign matter discharge control can be performed only at the start of the internal combustion engine and immediately after the start, and the deviation between the target cam phase and the actual cam phase can be minimized.

  When the foreign matter discharge control is performed, the feedback control of the actual cam phase with respect to the target cam phase temporarily stops. It should be prohibited because it causes engine output characteristics and exhaust gas deterioration. In the fourth embodiment and the fifth embodiment, there is an effect of restricting the foreign matter discharge control from being performed more than necessary.

A configuration example of an embodiment of the present invention will be described with reference to the drawings.
FIGS. 1 and 2 show configuration examples of the internal combustion engine (engine) described in the first to fifth embodiments.

  In this embodiment, the oil control valve control device is included in the engine control device 13.

  The engine 3 is composed of a plurality of cylinders (not shown), and the air introduced into the cylinder 101b is taken from the inlet portion 102a of the air cleaner 102 and passes through the intake air amount sensor (air flow sensor 25) to control the intake air amount. The collector 106 is entered through the throttle body 140 in which the electric throttle valve 140a is accommodated. The opening degree of the electric throttle valve 140a is controlled by the engine control device 13. The air sucked into the collector 106 is distributed to each intake pipe 107 connected to the cylinder 101b of the engine 3 and then guided to the combustion chamber 101c formed by the piston 101a, the cylinder 101b and the like. In addition, a signal representing the intake air amount is output from the air flow sensor 25 to the engine control device 13. Further, a throttle sensor 27 for detecting the opening degree of the electric throttle valve 140 a is attached to the throttle body 140, and its signal is also output to the engine control device 13.

  On the other hand, fuel such as gasoline is pressurized from a fuel tank (not shown) by a fuel pump (not shown), and then combusted from an injector 54 provided in the cylinder 101b through a fuel pipe (not shown). It is injected into the chamber 101c. The fuel injected into the combustion chamber 101 c is ignited by the spark plug 109 by the ignition signal that has been increased in voltage by the ignition coil 108.

  The rotating body 1 and the rotation angle detection sensor 2 attached to the crankshaft 101d of the engine 3 output a signal indicating the rotational position of the crankshaft 101d to the engine control device 13, and are attached to the intake camshaft 100 of the intake valve 121. The rotating body 118 and the cam angle sensor 117 thus output output an angle signal representing the rotational position of the cam shaft to the engine control device 13. In this embodiment, the crankshaft 101d is provided with the mechanical oil pump 150, but it may be an electric oil pump as well as a mechanical oil pump.

  The exhaust pipe 209 is provided with an air-fuel ratio sensor 208 that detects the oxygen concentration in the exhaust gas and outputs a detection signal to the engine control device 13, an exhaust gas purification catalyst 210, and the like.

  Next, the configuration of the engine control device 13 and the engine control method will be described with reference to FIG. The main part of the engine control device 13 is constituted by an MPU 203, an EP-ROM 202, a RAM 204, an I / O LSI (input / output circuit 201) including an A / D converter, and the like. Crank rotation angle detection sensor 2, cam angle sensor 117, water temperature sensor 28 for measuring engine cooling water temperature, intake pipe internal pressure sensor 29 for measuring pressure in the intake pipe, etc. A predetermined calculation process is executed, and various control signals calculated as the calculation results are output. A predetermined number of predetermined control signals are output to the fuel pump (not shown), each injector 54, the ignition coil 108, the oil control valve 151, and the like. A control signal is supplied to execute fuel injection amount control, ignition timing control, cam phase control, and the like.

  Next, the structure and operation of the variable valve timing mechanism will be described with reference to FIGS.

  A variable phase cam pulley 30 is provided at one end of the intake camshaft 100. The phase variable cam pulley 30 is a continuous phase variable type.

  One end of the exhaust camshaft 130 is provided with a cam pulley 31 whose phase does not change.

  A crank pulley 32 is fixed to the crankshaft 101d.

  The phase variable cam pulley 30 and the cam pulley 31 are driven by a crank pulley 32 via a timing belt 33.

  The phase variable cam pulley 30 incorporates an actuator driven by hydraulic pressure. The structure of this actuator will be explained. A vane 40 fixed to the intake camshaft 100 is built in the variable phase cam pulley 30, and there is a space around the vane 40 in which the vane 40 can operate in the rotation direction. Is provided. This space is divided into an advance chamber 41 and a retard chamber 42 by a vane 40. The advance chamber 41 is connected to a phase advance hydraulic passage 156, and the retard chamber 42 is connected to a phase retard hydraulic passage 157. .

  The oil control valve 151 (OCV) 151 includes a solenoid 43, a plunger 44, a housing 45, a spool 46, and a spring 47. When no current is supplied to the solenoid 43, the spool 46 is pushed by the spring 47 and the right side of FIG. Located in the direction.

  When a current is supplied to the solenoid 43, the plunger 44 pushes the spool 46 in the left direction in FIG. 4, so that the force of the spring 47 is overcome and the spool 46 moves in the left direction. The amount of movement of the spool 46 in the left direction increases in proportion to the amount of current supplied to the solenoid 43.

  The housing 45 includes a hydraulic pressure supply port 50, an advance port 51, a retard port 52, and a drain port 48. The hydraulic pressure supply port 50 is retarded by an oil passage 155, and the advance port 51 is retarded by a phase advance hydraulic passage 156. The angular port 52 is connected to the phase retarding hydraulic passage 157, and the drain port 48 is connected to a drain passage (not shown).

  As shown in FIG. 5A, when the spool 46 is positioned in the right direction in the figure, the hydraulic pressure supply port 50 and the retard port 52 communicate with each other, and at the same time, the drain port 48 and the advance port. 51 communicates. Therefore, the oil supplied from the oil pump 150 is guided to the retard chamber 42, and the oil in the advance chamber 41 is discharged to the oil pan through the drain passage. Therefore, the vane 40 changes the phase in the retarding direction with respect to the phase variable cam pulley 30.

  When the spool 46 is positioned at the center as shown in FIG. 5B, the hydraulic pressure supply port 50, the advance port 51, the retard port 52, and the drain port 48 are all closed. For this reason, there is no oil flow, and the vane 40 does not change the phase with respect to the phase variable cam pulley 30.

  As shown in FIG. 5C, when the spool 46 is located in the left direction in the figure, the hydraulic pressure supply port 50 and the advance port 51 are in communication with each other, and at the same time, the drain port 48 and the retard port 52 communicates. Therefore, the oil supplied from the oil pump 150 is guided to the advance chamber 41, and the oil in the retard chamber 42 is discharged to the oil pan through the drain passage. Therefore, the vane 40 changes the phase in the advance direction with respect to the phase variable cam pulley 30.

  Here, since the vane 40 is fixed to the intake camshaft 100 and the variable phase cam pulley 30 is connected to the crankshaft 101d via the timing belt 33, the change in the phase between the vane 40 and the variable phase cam pulley 30 It is agreed to the change in phase between the shaft 101d and the intake camshaft 100.

  The phase (actual cam phase) of the intake camshaft 100 with respect to the crankshaft 101d is a signal indicating the rotational position of the crankshaft 101d output from the rotation angle detection sensor 2 and the intake camshaft 100 output from the cam angle sensor 117. It is calculated by the engine control device 13 using a signal representing the rotational position.

  The engine control device 13 feedback-controls the current value of the solenoid 43 so that the target cam phase calculated based on the operation state detected from each sensor is equal to the actual cam phase.

  Here, as a method of controlling the current value of the solenoid 43, a method of changing a ratio (duty ratio) between a time during which a voltage is applied to the solenoid 43 and a time during which the voltage is not applied within the unit time is used.

  When the duty ratio is increased, the current value of the solenoid 43 increases, the position of the spool 46 becomes as shown in FIG. 5C, and the actual cam phase moves in the advance direction. When the duty ratio is reduced, the current value of the solenoid 43 decreases, the position of the spool 46 becomes as shown in FIG. 5A, and the actual cam phase moves in the retard direction. When the duty ratio is an intermediate value, the current of the solenoid 43 also becomes an intermediate value, the position of the spool 46 is as shown in FIG. 5B, and the actual cam phase does not change. The duty ratio at which the actual cam phase does not change and the position of the solenoid 43 are hereinafter referred to as a neutral point.

  Next, the operation when the oil control valve 151 is clogged with foreign matter will be described with reference to FIG.

  When the spool 46 moves to the left side in the drawing and the actual cam phase moves in the advance direction, if the foreign object 60 is clogged between the housing 45 and the spool 46 in the retard port 52, the spool 46 Cannot move right inside. Therefore, the actual cam phase continues to move in the advance direction, and the actual cam phase is advanced from the target cam phase.

  The engine control device 13 feedback-controls the current value of the solenoid 43 so that the target cam phase and the actual cam phase are equal. In this state, the solenoid 43 is used to move the actual cam phase in the retard direction. The drive duty ratio is controlled to be small.

  As a result, the spool 46 is pressed in the right direction in the figure, so that the foreign matter 60 is sandwiched between the housing 45 and the spool 46 and is not flown.

  That is, if the current value of the solenoid 43 is feedback-controlled so that the target cam phase and the actual cam phase become equal when the foreign matter clogging occurs, the target cam phase and the actual cam phase are deviated without removing the foreign matter. The state will continue.

  In order to remove the foreign matter 60, the spool 46 is moved to the left in the drawing to increase the gap between the housing 45 and the spool 46, and the foreign matter 60 is released and washed away with oil (foreign matter discharge control). I need it. Hereinafter, a method of foreign matter discharge control will be described.

  Examples for the first to third embodiments will be described.

  FIG. 7 is a time chart showing the target cam phase and the drive duty ratio of the solenoid 43.

  The engine control device 13 detects the operating state and the actual cam phase and calculates the target cam phase every predetermined time (for example, every 10 ms).

  Here, when the operation state changes at the timing of t1 and the target cam phase changes to the advance side, the output duty ratio selection is set to the feedback stop (Open) state, and the solenoid duty ratio indicates that the cam phase is in the advance direction. The maximum value 100% is output so as to move.

  If the target cam phase change amount at the timing t1 is DA1, an appropriate characteristic is selected according to the oil temperature condition from the operation characteristics of the variable valve timing mechanism due to the difference in temperature condition shown in FIG. The open state duration TC1 is calculated by calculating back the phase angle change time with respect to DA1.

  After the Open state continuation time TC1 elapses from the timing of t1, the output duty ratio selection is set to the feedback state, and the solenoid duty ratio is returned to the feedback control so that the target cam phase and the actual cam phase become equal.

  Similar to the timing of t1, the output duty ratio selection is set to the feedback stop (Open) state at t2 and t4, but this outputs 0% which is the minimum value so that the cam phase moves in the retarding direction.

  Since the target cam phase change amount DA3 is larger than DA1 at the timing t3, the Open state duration TC3 calculated from the operating characteristics of the variable valve timing mechanism due to the difference in temperature conditions shown in FIG. 8 is also larger than TC1.

  Next, an example for the fourth embodiment will be described.

  FIG. 9 is a time chart showing the target cam phase and the drive duty ratio of the solenoid 43.

  In this embodiment, a target cam phase change count that adds the number of times the target cam phase change amount changes from 0 to a non-zero state is added to the first embodiment, and the target cam phase change count reaches 3. Then, the control is changed so that the output duty ratio selection is set to the feedback stop (Open) state.

  By doing in this way, the frequency which becomes a feedback stop state can be reduced.

  Next, an example for the fifth embodiment will be described.

  FIG. 10 is a time chart showing the target cam phase and the drive duty ratio of the solenoid 43 with respect to the engine speed.

  This embodiment adds a target cam phase change count that integrates the number of times the target cam phase change amount is changed from 0 to a non-zero state with respect to the first embodiment, and the target cam phase change count is 1 or less. If there is, the control is changed so that the output duty ratio selection is in a feedback stop (Open) state. In addition, a process of clearing the integrated value of the target cam phase change count to 0 when the engine is stopped is added.

  In this way, the foreign matter discharge control can be performed in accordance with the operation in which the target cam phase is advanced from the most retarded position after the engine is started.

  In vehicles such as hybrid vehicles that perform idle stop, the engine is frequently started and stopped, and the target cam phase often differs greatly when the engine is stopped and when it is rotating. Therefore, the target cam phase changes greatly every time the engine is started.

  In other words, every time the engine is started, a condition that is convenient for carrying out the foreign matter discharge control is satisfied. Therefore, the foreign matter discharge control is executed at the time of starting the engine and immediately after the start so that the feedback stop state is not caused during normal operation. Can be.

  As mentioned above, although the embodiment provided with some examples of the present invention was explained in full detail, the present invention is not limited to the embodiment and departs from the spirit of the present invention described in the claims. Without modification, various changes can be made in the design.

  In the above embodiment, the internal combustion engine provided with the valve opening characteristic adjusting device for the intake valve has been described. However, the present invention can also be applied to an internal combustion engine provided with the valve opening characteristic adjusting device for the intake valve and the exhaust valve. Is clear.

  Further, although the variable valve timing mechanism has been described, a variable valve lift control device may be used.

  In each embodiment, the control of the intake valve 121 has been described, but the exhaust valve 120 can be similarly implemented.

It is a block diagram of an engine control system. It is a block diagram of an engine control system. It is a block diagram of an engine control apparatus. It is a structural diagram of a variable valve timing mechanism. It is operation | movement explanatory drawing of an oil control valve. It is explanatory drawing of the foreign material clogged state of an oil control valve. It is an operation time chart of a target cam phase and a solenoid control parameter. It is an operation characteristic figure of a variable valve timing mechanism by the difference in temperature conditions. It is an operation time chart of a target cam phase and a solenoid control parameter. 6 is an operation time chart of a target cam phase and solenoid control parameters with respect to engine speed.

Explanation of symbols

1,118 Rotating body 2 Rotation angle detection sensor 3 Engine 13 Engine control device 25 Air flow sensor 27 Throttle sensor 28 Water temperature sensor 29 Intake pipe internal pressure sensor 30 Phase variable cam pulley 31 Cam pulley 32 Crank pulley 33 Timing belt 40 Vane 41 Advance angle chamber 42 Slow Square chamber 43 Solenoid 44 Plunger 45 Housing 46 Spool 47 Spring 48 Drain port 50 Hydraulic supply port 51 Advance port 52 Delay port 54 Injector 60 Foreign object 100 Intake camshaft 101a Piston 101b Cylinder 101c Combustion chamber 101d Crankshaft 102 Air cleaner 102a Inlet part 106 Collector 107 Each intake pipe 108 Ignition coil 109 Spark plug 117 Cam angle sensor 120 Exhaust valve 121 Intake valve 140 Throttle body 1 0a electrically controlled throttle valve 150 Oil pump 151 oil control valve 155 oil passage 156 phase advance hydraulic passage 157 phase retarding hydraulic passage 201 output circuit 202 EP-ROM
203 MPU
204 RAM
208 Air-fuel ratio sensor 209 Exhaust pipe 210 Exhaust gas purification catalyst

Claims (8)

A control device for an oil control valve that drives an actuator to adjust the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine,
The controller is
Feedback means for controlling the actuator so that the actual cam phase, which is the rotational phase of the camshaft relative to the rotation of the crankshaft, is equal to the target cam phase determined based on the operating state of the internal combustion engine;
A control device, wherein the actuator is driven with a driving amount larger than a driving amount of the actuator by the feedback means for a predetermined time after the target cam phase changes.   The actuator is driven by energizing a solenoid coil. A control device for an oil control valve that drives an actuator by energizing a solenoid coil to adjust the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine,
The controller is
Feedback means for energizing the solenoid coil such that the actual cam phase, which is the rotational phase of the camshaft relative to the rotation of the crankshaft, is equal to the target cam phase determined based on the operating state of the internal combustion engine;
A control apparatus, wherein a control is performed so that a voltage larger than the energization of the solenoid coil by the feedback means flows through the solenoid coil for a predetermined time after the target cam phase changes. A variable valve timing mechanism that adjusts the opening / closing timing of a valve driven by the camshaft by changing the rotational phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine using the hydraulic pressure of the hydraulic oil;
An oil pump that pressurizes the hydraulic oil and discharges it to the variable valve timing mechanism, and is provided between the variable valve timing mechanism and the oil pump, and by adjusting the amount of movement of the spool by controlling the actuator, An oil control valve for adjusting the hydraulic pressure to the variable valve timing mechanism;
An operating state detecting means for detecting an operating state of the internal combustion engine;
Target cam phase calculating means for calculating a target cam phase based on the detection result of the operating state detecting means;
An actual cam phase detecting means for detecting the rotational phase of the camshaft relative to the rotation of the crankshaft;
An oil control valve control device for an internal combustion engine comprising means for feedback-controlling the actuator so that an actual cam phase is equal to a target cam phase,
Control amount change control means for controlling the actuator with a predetermined control value different from the control value calculated by the feedback control means only for a predetermined time after the target cam phase changes is provided. Oil control valve control device for internal combustion engine.   5. The oil control valve control device for an internal combustion engine according to claim 4, wherein the predetermined control value is set so that a rotational phase of the cam shaft operates in a direction in which the target cam phase changes.   The oil control valve control device for an internal combustion engine according to claim 4 or 5, wherein the predetermined time is set based on a change amount per unit time of the target cam phase.   The number of times the target cam phase has changed is integrated, and when the integrated value reaches a predetermined value, the actuator is controlled with a predetermined control value different from the control value calculated by the feedback control means. 5. The oil control valve control device for an internal combustion engine according to claim 4, wherein the integrated value is cleared.   The number of times the actuator is controlled with a predetermined control value different from the control value calculated by the feedback control means between the start and stop of the internal combustion engine is limited to a predetermined number or less. An oil control valve control device for an internal combustion engine according to claim 4.

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